The concepts of the present invention encompass a form of rotary machines embodying parallel and splayed axis shafts with eccentric and non-eccentric rotors. In the prior art, the axis of rotation is through the geometric center of the rotor, thereby limiting the possible configurations. Typical rotary engine patents use parallel axis configurations meaning that the axes of rotation are parallel to each other and all rotors rotate in a planar circular arc perpendicular to these axes. The shifting of the center of rotation away from the center of geometry (i.e., eccentricity) allows for multiple rotor configurations (four, five, and six). This concept of eccentricity has remained unused in rotor design because no one has sought to modify the basic philosophy of the prior Colbourne rotary concept and its relative uniqueness and simplicity. Of the many innovations that extend from the Colbourne concept, none of them have strayed from the fundamental concept of the Colbourne theme.
In addition, and related to this concept of eccentricity, is the concept of radial axis machines where the axis of rotation is skewed or tilted in a radial pattern around a central fixed axis. The tilting of the axis causes varying degrees of eccentricity to occur in the rotor design. This skewing condition of the axes culminates when the radial axes are perpendicular to each other at 90 degrees and eccentricity is zero. Moving from parallel axis to radial axis machines, where the axis of rotation is not parallel to the axes of adjacent rotors, allows for a greater diversity of rotary machines not before envisioned. This movement of the axis from parallel to radial generates machines where the rotors do not rotate on a plane but rotate on spherical surface.
History shows multiple patents that describe three or four rotor machines that are all based on parallel axis. This creates a machine where all rotors are revolving about parallel axis shafts and their construction geometries and rotational movements are on a planar surface. In addition, the axis of rotation falls directly through the center of the rotor shape (zero eccentricity). This limits the possible configurations to groupings of three or four rotors. Due to the geometries involved with keeping the rotors tangent to each other as they rotate through 360 degrees, parallel axis machines with a single volume chamber cannot be defined with more than four rotors. This does not mean that they can not be placed together in adjacent groupings to create more than one chamber, but in all cases, there can not be more than four rotors either applying work to or extracting work from the cycle of the machine.
In an eccentric configuration, the axis is moved off the center of the oval shaped rotor (referred to as eccentricity). This results in an extension of the four-rotor design and allows for the creation of five- and six-rotor configurations where six is the maximum practical configuration. Although seven rotors and above is geometrically possible, the resulting rotor configuration is not practical, since the resulting shape would not allow for a reasonable mechanical configuration. For example, the inclusion of an output shaft.
In the past, four-rotor design has been the basis for rotary machines. The introduction of eccentricity allows for five and six flat or planar rotor configurations. Five and six rotor configurations expose more surface area to the chamber, thereby increasing their possibility to do work for each machine cycle which also use the “teardrop” shape rotor where one tip has a radius and the other tip forms a vertex. These five- and six-rotor configurations create a natural port as the rotors move through their cycle.
It is true that the four-rotor configuration could be scaled or have multiple groupings to equal this work gain, but that would require a significant increase in machine size. Thus the five- and six-rotor rotary machines are far more efficient for a given physical size.
Although this machine depicts a typical arrangement for an engine configuration, this concept of eccentric rotors on a rotary machine could apply to other embodiments such as pumps. To get the rotors to work in unison and in co-rotation, a gear set is required that provides the phasing of the rotors to produce the working chamber.
Eccentricity in Rotor Definition
The concept of eccentricity in rotor definition has not been used because no one has sought to modify the basic philosophy of the Colbourne rotary concept from its relative uniqueness and simplicity. Of the many innovations that extend from the innate beauty and simplicity of the Colbourne concept, none have strayed from the fundamental concept of the Colbourne theme until the ideas set fourth in this document.
The introduction of eccentricity into the rotary configuration creates the following benefits over existing parallel axis configurations: The dynamic (moving) porting simplifies the methods of engine cycling; Allows for multiple (4+) rotor configurations, operating in both parallel axis and non parallel axis configurations; Increased torque outputs due to the induced lever arm created from the offset axis; Increased work output due to the increased surface area the multiple rotors (4+) permit for a given chamber volume; Reduced physical size required to configure the machine; Larger chamber volumes for a given physical size; Easy assembly using bevel gears.
For parallel axis systems, the rotors are all moving on planes perpendicular to the axis of rotation.
The introduction of a radius tip at one or both ends of the rotor affects the eccentricity, thereby shifting the rotor rotation axis from the center of the rotor geometry. The addition of a radius tip causes several desirable outcomes: Radius tips create a chamber volume, which can be altered in size based on the application of the machine; A radius tip produces a complimentary surface that as the rotors interact with each other, there is more surface area in tangential contact rather than a singular vertex; A radius tip also creates a region of the rotor suitable for the placement of a load-bearing crankshaft.
Radial axis configurations of the rotary engine have also not been exploited in the past. Parallel axis embodiments are the common machine configuration. The introduction of eccentricity into the basic four-rotor configurations has allowed the creation of five- and six-rotor rotary machines. Eccentricity also allows us to move to radial axis configurations where the axis of rotor shafts are not parallel, but can be splayed from a central axis to form a right circular cone.
When one introduces a radial angle into the axis of rotation, the rotors can no longer operate in a planar or flat environment but must now rotate relative to a spherical surface. This radial angle or “splaying” of the shafts off of parallel introduces an eccentricity formed at the apex angles by the mapping of standard flat shapes (squares, pentagons and hexagons) onto spherical surfaces. Eccentricity is now formed naturally due to the radial array unlike in the flat conditions where one has the option to introduce it into their design. When dealing with radial arrays and spherical surfaces, there is a solution where the tip radius will maintain tangential contact with the sides of the adjacent rotor as it passes through its 360-degree cycle for any given amount of eccentricity due to apex angle and tip radius.
The addition of a radial tip is essential in the creation of a machine. As discussed previously, the radius tip allows for a volumetric area for either combustion or pump activities. The construction process is the same for the six-rotor lobe as it is for all other rotor designs. As with all other configurations described in this document, the resultant curve for the “long” side of the rotors is not a second order constant radius arc. It is a third order spline. Failure to describe it as such will yield rotor designs that will not work in “real life” applications.